1. Field of the Invention
The invention relates to radio frequency identification (RFID) readers, and in particular, to diagnostic communications between RFID readers.
2. Background Art
Radio frequency identification (RFID) tags are electronic devices that may be affixed to items whose presence is to be detected and/or monitored. The presence of an RFID tag, and therefore the presence of the item to which the tag is affixed, may be checked and monitored wirelessly by devices known as “readers.” Readers typically have one or more antennas transmitting radio frequency signals to which tags respond. Since the reader “interrogates” RFID tags, and receives signals back from the tags in response to the interrogation, the reader is sometimes termed as “reader interrogator” or simply “interrogator”.
With the maturation of RFID technology, efficient communication between tags and interrogators has become a key enabler in supply chain management, especially in manufacturing, shipping, and retail industries, as well as in building security installations, healthcare facilities, libraries, airports, warehouses etc.
Reading of tags often takes place in an environment where the readers and their antennas experience physical abuse, such as in a warehouse environment, where objects may impact the reader antenna. Determining whether a reader has failed, such as due to damage from an impact, can be difficult. Typically, first, it has to be noticed that the reader may not be operating properly. Next, an operator has to approach the location of the reader. The operator then places a tag in the vicinity of the reader to check whether the reader can read the tag, to verify operation of the reader. This process is manually intensive and time consuming.
Thus, what is needed are improved ways of detecting RFID readers that are not operating properly, and improved ways of diagnosing the particular problems.